Telephone networks typically utilize wired analog circuits to connect a user's telephone to the local exchange of the network. This interconnection of the user's telephone and the network is referred to as the "local loop." The arrival of affordable analog cordless telephones enables the use of radio to provide the link from an ordinary telephone subscriber to the local exchange. The drop-in costs for the radio technology have fallen and "wireless local loops" have become an economically viable proposition.
Many aspects exist that make wireless local loop (also referred to as "radio access") dissimilar from other local loop access alternatives, including wire and optical fiber. The numerous benefits of providing a wireless local loop are easily recognized. A short list of benefits includes providing terminal mobility, replacing obsolete copper cabling, providing access in a competitive environment, providing services to new areas, enhancing capacity of an existing network, providing back-up for deteriorating lines, and allowing fast deployment.
Although most of the global telecommunications network is based upon analog technology, broadband technology and fixed networks (e.g., Integrated Services Digital Network (ISDN) and Asynchronous Transfer Mode (ATM)) provide a new scope of applications. Such applications include providing video data over telephone lines and telephone services over cable television infrastructures.
A variety of digital wireless communication technologies exist today, including narrowband to wideband and point-to-point broadcast. One such digital communication system is the personal handy-phone system (PHS). The personal handy-phone system is a cordless telephone system that offers integrated telecommunication services, such as voice and data, via a universal radio interface. The personal handy-phone system offers digitalization of the communication system. In particular, the digital personal handy-phone system offers improved quality and effective use of frequencies.
Personal handy-phone systems comprise at least one base station, also referred to as a cell stations, and a plurality of corresponding personal stations, also referred to as handsets. The personal handy-phone system offers flexible inter-connectability wherein connection of a personal station with a plurality base stations at various locations such as the office, home, or outdoors is possible. The PHS standard is set forth by the Telecommunications Technical Committee of Japan in "Personal Handy Phone System", Japanese Telecommunications System Standard, RCR-STD 28.
The personal handy-phone system also offers connectability with existing communications networks. Connection is possible with analog telephone networks as well as digital networks.
Personal handy-phone systems are designed to provide wireless multimedia communications, terminal mobility, and complete two-way communications. Personal stations and base stations of the personal handy-phone system are configured to transmit and receive data via a plurality of data packets, also referred to as slots.
Personal handy-phone systems employ a microcellular structure. Utilization of a microcellular structure reduces base station construction costs, reduces terminal size, weight and power consumption, and enables handling of a high volume of communication traffic.
The base stations may be of a low power output type (i.e., 10 mW) generally for indoor applications, or a standard power output type (i.e., 20 mW) or high power output type (i.e., 100-500 mW) for outdoor applications. Group control functions may be implemented to increase communication channels in an area with heavy traffic whereby multiple base stations are controlled via the same control channel. Such stations may be arranged in a master/slave configuration.